make matplotlib mandatory

bac_analyze.py

@@ -12,11 +12,7 @@ import sys
 from collections import defaultdict
 from pathlib import Path
 
-try:
 import matplotlib.pyplot as plt
-    HAS_MATPLOTLIB = True
-except ImportError:
-    HAS_MATPLOTLIB = False
 
 
 def load_transactions(json_files: list[Path]) -> list[dict]:
@@ -208,10 +204,6 @@ def main():
         if not path.exists():
             sys.exit(f"Error: File not found: {path}")
 
-    # Check matplotlib early if graph requested
-    if args.graph and not HAS_MATPLOTLIB:
-        sys.exit("Error: matplotlib is required for graphs. Install with: pip install matplotlib")
-
     # Load categories
     if not args.categories.exists():
         sys.exit(f"Error: Categories file not found: {args.categories}")